Safety-valve for steam-boilers.



PATENTED MAY 5, 1908.

B. J. CLARKE. I SAFETY VALVE FOR STEAM BOILERS.

APPLICATION FILED JUNE 1 1906.

3 2 SHEETS- SHEET 2.

' 3141mm? Q/Vitneomo k6 as: 6cm,

EDWARD J. CLARKE, OF SCRANTON, PENNSYLVANIA.

SAFETY-VALVE FOR STEAM-BOILERS.

. Specification of Letters Patent.

Patented m 5, 1908.

Application filed-Tune 13, 1906. Serial No. 321,485.

To all whom it may concern:

Be it known that I, EDWARD J. CLARKE, a citizen of the United States of America, residing at Scranton, in the county of Lackawanna and State of Pennsylvania, have invented new and useful Im rovements in Safety-Valves for Steam-Bo ers, of which the following is a specification.

This invention relates to improvements in safety valves for steam boilers, the main ob ject of the invention being to provide a valve controlled by the temperature as it exists in the ordinary operation of steam boilers, and utilizing a thermostat or the ex ansion of metal as the operating medium, w ereb the escape of steam or gases from the boi er is permitted when the temperature in generation reaches a determined degree or an inconsistent condition of temperature exists to obviate all liability of an explosion.

A further object of the invention is to provide a thermostaticallvoperated valve which, in one form of em odiment, may be used in conjunction with an ordinary safety valve or indipendently to effect the exhaust of steam an gases from the boiler when a dangerous temperatureor pressure is reached, and which, in another form of embodiment, is adapted to be operated by both temperature and pressure, independently or conjointly, the construction being such as to permit adjustment of the operating medium to act at any degree of temperature within reasonable and safe limits.

Still another object of the invention is to provide a thermostatic safety valve which will operate to allow exhaust of steam from the boiler, so as to effect a ositive relief, in the event of the ordinary sa ety valve or the valve member of the thermostatic valve sticking to its seat and failing to open under maximum steam pressure.

My invention operates on the principle 7 that a certain temperature should exist, in

accordance with established thermo-dynamics steam tables, with a determined steam pressure in the boiler, and such temperatures and such pressures should always be reasonably consistent, otherwise a condition, perha s not indicated by the pressure gage, is he le to ensue and cause an explosion, notwithstanding the fact that the pressure gage through defect in action or other causes may show that the pressure of steam is much less than that which the boiler is designed to stand and below that under which the ordinary safety valve is set to open. If at any time during the operation of the boiler in the generation of steam the generating temperature should rise materially above that at which the intended maximum pressure is generated, the valve will operate to permit of the exhaust of the excess pressure to the atmos here.

In t e accompanying drawings,Fig'm'e 1 isa vertical section of a combination safety valve embodying my invention, which valve is adapted to operate under both thermostatic action and steam pressure. Figs. 2

and 3 are horizontal sections thereof, taken respectively on the lines 22 and 33' of Fig. 1. Fig. 3 is a sectional view showing a modification in the construction of the bonnet. Fig. 4 is a vertical section of a valve opened solely by thermostatic action. Fig. 5 is a horizontal section of the same, taken on line 5 5 of Fig. 4.

Referring to the drawing, the numeral 1 designates the valve body, which may be of any suitable form and construction, but as shown is of generally circular form and provided with an exhaust port or passage 2 and a valve seat 3 at the upper end of said passa e. The body has an angular surface 4 be ow which is a threaded extension 5 adapted to be screwed into a suitable receiving 0 ening in the to of the boiler shell A, as s own in Fig. 1, t e angular surface 4 permitting of the a plication of a wrench or other suitable too to enable the valve to be conveniently applied and removed.

The valve body terminates at its upper end in an externally threaded reduced portion 6, to which is connected the lower threaded end of a bonnet or casing 7, provided with a desired number of ports 8 for the direct passage of the escaping, steam or gases to the atmosphere. If desired, however, these ports ma be dispensed with and the bonnet provide in lieu thereof with a connection 9 as shownin Fig. 3 for the attachment of an exhaust pipe to lead the escaping steam or gases to any desired point of discharge.

- bonnet and passes at its-lower end through the valve body and boss 12, the said lower end of the stem being formed with a reduced extension 15 projecting below the valve.

The lower end of the stem and the receivin opening or passage therefor'inthe valve an boss have a threaded engagement to permit the valve to be adjusted to regulate its seating action. The upper end of the stem extends through a'gul e plug 16 threaded for adjustment in a threaded opening in the top of the bonnet, and is provided with a head 17, whereby it may be adjusted to regulate the movement of the valve. The plug 16 is adapted to be heldin adjusted position by a lock nut 17 and bears. at its lower end upon a pressure head 18. Surrounding the stem between this head and the valve 10 is a coiled pressure s ring 19 which holds the valve seated un er a determined pressure, which pressure may be regulated as desired by adjusting the plug 16. The plug receiving ope in the top of the bonnet'extends through a oss or enlargement 20 which is externally threaded for the reception of the lower threaded end of a dome cap 21, which incloses and shields the projecting portions of the plug and valve stem.

From the threaded extension 5 depends a oke or open frame. 22 which projects down into the steam space A and terminates above the highest normal water level. The base of said yoke or frame is formed with a threaded opening receiving an adjusting and supportmg screw 23. The upper end of this screw is j'ournaled in and supports a head 24 carrying metallic expansion bars or strips 25.. These strips are suitably connected at their lower ends to the head and are divergently arranged and pivotally connected at their upper ends to oppositely arranged levers 26. The said levers 26 extend horizontally across the port 2 when the valve is closed and are seated and pivoted at their outer ends in recesses 27 formed in the valve body and pivotally attached at their inner ends to a head 28 arranged to slide upon the portion 15 of the stem and abutting a ainst the lower endof the valve boss 12. t .will be observed that the u per ends of the expansio'n bars are iv ote to the intermediate portions of the evers 26, which latter are raised and lowered as the barsexpand and contract and thereby through the connections described impart pressure to force the valve open against the resistance of the spring and to permit it to close under the act1on of said s ring. The bars, levers and their supports orm a thermostat for controlling the action of the valve independent of steam pressure, and it will be observed that the head 28 by being slidably mounted on the portion 15 permits the valve to freely open under s'team pressure in the usual way.

It will, of course, be understood that the valve may be constructed in any suitable manner for application to the boiler, and that the parts may be modified in various ways as may be deemed preferable, so long as the principle of operation is reserved.- It will also be understood that may employ any preferred form of ex ansion means for operating the valve, and t at the valve may be employed independent of or in connection with a pressure safety valve of known types in use,

Thevalveis adjusted after the device is applied to the boiler to regulate the pressure 0 the spring 19 to allow the valve member 10 to 0 en under the pressure of the steam when the atter rises to the desired maximum degree, the position of the device being such that the yoke 22 projects down into the top or steam space of the boiler, so that the bars 25 will be affected by the temperature within said space.

When the steam ressure rises above the safety limit, the va ve 10 will be caused to open thereby to allow of the exhaust of the extra ressure, so that the device will subserve t e function of the ordinary safety pressure valve. When the temperature in the steam s ace of the boiler exceeds the degree which should exist when the steam ressure reaches the safety limit, the expansion bars 25 lengthen and transfer motion to the levers 26, which, in turn, raise the valve 10 against the resistance of the spring 19, thus ermitting theexcess steam to exhaust. Ey this means, ifthe valve should stick so that it will not open under steam pressure when the this manner an to perform the function ofan ordinary pressure safety valve double security is afforded in the way.of preventing an ex losion. The action of the thermostat may e regulated to accord with the degree of pressure of the spring 19 by the adjusting screw 23,. and by means of said screw and the adjustable connection between the valve and stem 14 the parts may be adjusted while the valve is in action to adapt the valve to oper-' ate with any desired-degree of sensltlveness.

and yoke is a coiled spring 32.

Hence, it will be seen that if through sticking or any other cause the valve should not be opened by steam pressure, it will be opened by the thermostat to exhaust the excess pressure before an explosion occurs.

In the embodiment of the invention disclosed in Fi s. 4'and 5, I have shown a valve normally he d closed by the thermostat and adapted to be opened by the expansion of the thermostat when the temperature in the boiler rises to a dangerous degree to allow of the esca e of the steam and thereby obviate any lia ilityof an explosion. This valve may be used upon a boiler equi ped with an ordinary steam safety valve an will operate entirely independently thereof to insure safety from dangerous conditions arising from an overgeneration of the steamif such safety valve should not work. ,As shown, the construction of this valve is generally the same as that shown in Fig. 1, the valve body, yoke, disk valve and thermostat being of the same general form and type except that the sprin mechanism for holding the valve seate against steam pressure is dispensed with and the bonnet or casing 7 correspondingly shortened, the o ening in the top of the casing being-close( by a perforated ca 21. The disk valve 10 in this form of the lnvention is rovided with a depending screwthreade socket 12 to receive a screw stem 14 projecting upwardly from the head 28, wherebv the valve is fi'xed to the head and normally held by the levers 26 and thermostatic bars closed against the .exhaust of steam pressure. The valve is rovided with lugs 17 by which it may be 8.(j1lSt6d on the stem 14* to regulate its seating action under the operation of the'thermo'stat. The metallic ex ansion bars or strips 25 also differ slight y in construction from those shown in Fig. 1, in that one of the bars is made longer than the other and pivoted thereto, as indicated at 25*, and provided at its lower end with a head 25* recessed to form a journal for the upper headed end of a screw stem 29 fitted to turn and slide freely in an opening in the base of the yoke 22. Below the yoke the stem carries-a nut 30 and a washer 31, and surrounding the stem between the washer By this construction the lower ends of the expansion bars are secured to the yoke in such manner as to permit a yielding action of the connection to'prevent distortion or injury to the parts from any tendency to excessive contraction of the bars. tion may be employed, if desired, upon the valve construction shown in Fig. 1. The 0' eration of this form of valve will be readi y understood from the fore oing description.-

Havin thus described t e invention, what is claime as new is 1.. A safety valve for steam boilers, c0n1- This form of connec-- .therein, a thermostat suplported upon the bottom of the casing in ependent of the valve, and an operative connection between the thermostat and valve, whereby the expansive action of the thermostat will open the valve. 1

4. A safety valve for steam boilers comprising a casing, levers pivotally mounted therein, a head pivotally connected with the levers, a valve arranged in the casing and adapted to be operated by the head, and a thermostat supported by the casing and operatively connected with the levers.

5. A safety valve for steam boilers comprising a casing, a thermostat supported thereby, a valve-operating device controlled by the thermostat,"and an escape valve in the casing ada ted to be opened by said device, said valve the thermostat.

6. A safety valve for steam boilers comprising a casing having an escape passage and a depending portion, .a perforated bonnet carried by the casing, an esca e valve controlling the assage and adapte to open upwardly into t e bonnet, and a thermostat supported by the de nding portion of the casing and operative y connected with the valve, said valve and thermostat being relatively adjustable.

7. A safety valve for steam boilers, co prising a casing, a thermostat carried thereby, means for regulating the 'action of the thermostat, a valve operating means 0 erable' by the thermostat, and an escape va ve adjustably connected with said means, and

adapted to be 0 ned thereby upon the eX- pansion of the t ermostat.

8. A safety valve for steam boilers comprising a casing, an escape valve arran ed therein, a head for operatin the va ve, levers pivotally connected with the casing andhead, and a thermostat comprising dieing adjustable with relation to vergent bars supported at their lower ends by the casing and ivotally-connected at their upper ends witthe levers.

9. A safety valve for steamboilers comprising a casing having an outlet passage and a de endin yoke, an esca e valve controlling t e out et passagalva ve-ocrating mechanism pivotal y mounted wit in the outlet passage, and a thermostat supported by the yoke and connected with the valveoperating mechanism.

10. A safety valve for steam boilers comprising a casing, a thermostat supported thereby, adjusting means for regulating the action of the thermostat, and an escape valve adapted to be 0 ened by the thermostat and adjustable with relation thereto.

11. A safety valve for steam boilers comprising a casing, a thermostat carried thereby, an escape valve adapted to be opened by the thermostat, means for regulating the action of the thermostat, and means for regulating the action of the valve.

12. A safety valve for steam boilers including a casing, an escape valve therein, and thermostatic means for opening the valve, .said valve and thermostatic means being relatively adjustable.

13. A safety valve for steam boilers comprising a casing, an escape valve. therein, a thermostat supported b the casing and operative to open the va ve, and means for permitting the valve'to open independent of the thermostat.

14. A safetyvalve for steam boilers comprising a casing, a thermostat supported thereby, a valve adapted to be opened by the thermostat, a movable connection between the valve and thermostat, permitting the valve to open independently under steam .pressure, and means for setting the valve to open under different pressures.

15. A safety valve for steam boilers-comprising acasing, a thermostat supported thereby, a valve adapted to be opened by the thermostat, and an operative connection between the thermostat and valve, whereby the valve is adapted to open independently of the thermostat under steam pressure.

16. A safety valve for steam boilers comprising a casing, a thermostat supported thereby, a valve operative to be opened by the thermostat or to open independently thereof under steam pressure, pressure means for resisting the opening movement of the valve, and means for regulating the pressure means.

17. A safety valve for steam boilers comprising a casing, a thermostat supported thereby, an escape valve slidably connected with the thermostat for o eration thereby or movement independent y thereof under steam pressure, ressure-controlling means acting on the va ve, and adjusting means connected with the casing for regulating the action of the thermostat.

18. A safety valve for steamboilers comprising a casing, an, escape valve therein, a thermostat su ported by the casing and including a hea and levers operativel connected therewith, said head beings 'dably connected with the valve, and adjusting.

means for regulating the action of the thermostat.

19'. A safety valve for steam boilers comprising a casing, ,a thermostat su ported thereby, an escape valve ada ted to e 0 erated by the thermostat and aving a sh 'ng connection therewith for in'de endent movement under steam pressure, a justin means for the valve, adjusting means for t e thermostat, a spring for normally holding the valve from movement, and means for varying the resistance of the spring.

20. A safety valve for steam boilers comprising a casing having an outlet assage and a de ending yoke, levers pivotally mounted withm the outlet passage, a head pivotally connected with the levers, a thermostat comprising bars pivotally connected at their upper ends wit the ,levers and supported at their lower ends by the yoke, an escape valve having a depending ortion engagin the head, a stem adjustab y connected wit the valve and having a portion slidably connected with'the head, means for operating the stem to regulate the seating action of the valve, a spring for resisting the opening movement of the valve, and means for varying the pressure of the spring.

21. In combination with a boiler, a valve casing in always open communication with the boiler, said casin having an outlet passage, a valve control ing the outlet passage, a thermostat supported within the steam space of the boiler wholly above the water level, means. operated by the expansion of the thermostat to open the valve, and means tively adjustable.

22. In combination with aboiler, a valve casing having an outlet passage communicating with the steam space of the boiler, a va ve controlling said passage, a thermostat su ported within the steam space of the boiler and wholly above the water line thereof, said thermostat being independent of the valve, and means operated by the expansion of the thermostat for opening the valve.

23; In combination with a boiler, a valve rendering the valve and thermostat relacasing having an outlet passage in always 0 en communication with the steam space of t e boiler, a valve controlling said passage, a thermostat independent of the. valve and supported within the steam space of the.

boiler, means operated bythe expansion of the thermostat to open the valve, and means whereby the valve is adapted to open independently under steam pressure.

24. In combination with a boiler, a valve casing having an outlet passage in direct communication with the steam space of the boiler, an escape valve'controlhng said passage o erating levers supported by the casconnected with the valve, and a.

lng an thermostat supported within the steam space i of the boiler and com rising ex ansion bars means operated 'by the expansion of the connected with said evers, w ereby upon thermostat to transmit open movement to the ex(pan,sionof said bars the valve be the valve, and means rendering the valve opene 25. In combination with a boiler, a valve I tively adjustable.

. casing having an outlet assage in always di- In testimony whereof, I aflix my signature rect communication wit the steam-space of in presence of two witnesses. the boiler, a valve controlling said passage, a EDWARD J. CLARKE. thermostat supported by the casing and sub-. Witnesses:

j ected always to the influence of thetempera- PAUL M. OoRsE, ture conditions within the steam space, l GEO. W. BUOKNAM.

' and thermostat independently and rela 15 

